Adults who have been in the affected area since late July with flu-like symptoms, fever, cough or difficulty breathing should seek immediate medical attention, health officials say.

The source of the illness has not been conclusively identified more than a week after people began getting sick.

There has been a third death in the Legionnaires' disease outbreak in New York City. Officials said the number of cases has grown to 67, including those three deaths. Legionnaires' is a severe form of pneumonia that doesn't spread from person to person,